package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    //      进入页面返回是否关注
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;
    @Override
    public Result isFollow(Long followUserId) {
        //        获取用户信息
        UserDTO user = UserHolder.getUser();
        if (user==null){
            return Result.fail("请先登录");
        }
        Long userId = user.getId();
//        根据ID从follow表中查询数据
        Integer count = query().eq("id", followUserId).eq("user_id", userId).count();
        return Result.ok(count>0);
    }
//          点击关注或者取关按钮
    @Override
    public Result followOrNot(Long followUserId, Boolean isFollow) {
//        获取用户信息
        UserDTO user = UserHolder.getUser();
        if (user==null){
            return Result.fail("请先登录");
        }
        Long userId = user.getId();
//      根据isFollow判断是关注还是取关
//      如果是关注那么就set数据如果是取关那么 就remove数据
        String key = "follows:"+userId;
        if (isFollow){
//            是关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSave = saveOrUpdate(follow);
            if(isSave){
//                更新数据库成功那么就往Redis里面添加数据
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
//            是取关
//            注意这里移除指定元素需要给一个QueryWrapper
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserId));
            if (isSuccess) {
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }


        return Result.ok();
    }

    @Override
    public Result followCommons(Long otherUserId) {
//        获取共同关注

        Long userId = UserHolder.getUser().getId();
        String key1 = "follows:"+userId;
        String key2 = "follows:"+otherUserId;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if (intersect==null||intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> collect = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
//        查询用户
        List<UserDTO> users = userService.listByIds(collect).stream().map((user) -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());

        return Result.ok(users);
    }
}
